Perhaps you should try some spelling variations:
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hieu va » hieu qua
thai do » thay doi, thai den
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua
do va » do van, so va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky tang xa hoi. ((hieu va) or (lieu va)) thai do va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky tang xa hoi. ((hieu va) OR (lieu va)) thai do va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu cac ky tang xa hoi. ((hieu va) or (lieu va)) thai do va hanh vi cua tre*.